Formula for determining how many watts needed to light area

I'm refinishing my basement into a game room with a table tennis table and an air hockey table. Is there a formula to determine how many watts of light I need to light the area sufficiently? The area is 500 sq ft and the ceiling is 6'10" high. I will be using flourescent tube lights that will be recessed in the ceiling. I want it to be bright but no so bright that it causes a glare. Thank you for any help that you can give me.

Three 4 bulb 40 watt flourescent fixtures should do it. Go with 4 fixtures if this is a long narrow space over 30 some feet long. Put one in the middle and the other two a little closer to the ends than the middle. You can always disconnect one of the ballasts on each light if you want to use two bulbs instead of four in each fixture. Commercial buildings will use two switches with 3 conductor wire going to the lights. That way one switch runs two bulbs of all three lights and the other switch runs the other bulbs if you need the full amount of light. Wire it white(neutral) to all the white neutrals, black (hot) to the outside ballasts black hot wire, and red(hot) to the inside ballasts black hot wire. They have a ballast for the outside bulbs and a ballast for the inside bulbs.